1. Field of the Invention
The invention relates to a line feedthrough through a cover of a heating kettle of a reducing agent tank, in which at least one line penetrates an opening in the cover and is sealed off by means of a sealing element.
2. Description of the Prior Art
One known method for posttreatment of an exhaust gas from an internal combustion engine is the SCR method (selective catalytic reduction), in which the pollutant NO is reduced to N2 and H2O with the aid of liquid reducing agent. The liquid reducing agent is stored in a reducing agent tank and pumped from the reducing agent tank via a hydraulic line to a metering module which adds the reducing agent in metered quantities to the exhaust gas. A slosh pot which is always filled with reducing agent is disposed in the reducing agent tank. A heater is provided in this slosh pot that serves to thaw frozen reducing agent. Because of the heater, the slosh pot is generally called a heating kettle. The heating kettle is closed by means of a cover, and the cover has an opening through which at least one hydraulic line, as described above, and/or an electric line for contacting the heater located in the heating kettle, or optionally a sensor element, is guided. Since the reducing agent system operates at a predetermined system pressure, it is necessary for the pressure to be maintained in the heating kettle as well. Among other reasons, this is why the feedthrough of the line through the cover is sealed off by means of a sealing element. It is known from the prior art to seal off a line feedthrough of this kind with a potting composition in which the line is first extended through the cover through a narrow bore, and then a reservoir surrounding the bore and embodied on the cover is filled with the liquid/viscous potting composition. Finally, the potting composition hardens and performs the sealing off of the line feedthrough. The narrow bores have the disadvantage that the line can be damaged as it is pushed through them. However, they are necessary to prevent the still-liquid potting composition from escaping from the reservoir. It is accordingly not possible for a line that is provided with a plug connection, for instance, to be extended through the cover.